Tim McComsey, owner of TRyM Fitness, trainer, and dietician, goes over an exercise he sees done wrong too often in the gym: the ab wheel rollout. This will work your core hard, but is only effective if you do it correctly. Many people allow their backs to arch up or down as they begin to roll out from their knees. You want to keep your back as straight as possible with your belly button tight toward your spine to compact all the abdominal muscles. Start with mini partial rollouts and work your way toward the full extended rollouts. Form is very important as this exercise puts pressure on your lower back and we don't want to see anyone injured as they are trying to get into shape. Keep that stomach tight and follow Tim's lead. If your back starts to hurt or you notice it arching, check your form again and you will have stronger, more defined abs in no time.